Process of treating metalliferous materials for roasting, reducing, sintering, and like purposes.



` F. c. w. HMM.

PRocEsS'oF TBEA'TING METALuFER'ouS MATERIALS Fon Rom'NG, Rfioucm, SINTERING,

` No LIKE PURPOSES.

APPLICATION FILED bCT. 30. 1913.

' 1 ,189,313. Patented Julv 4, 1916;.-

Alti

` terials for Roasting,

Finanztreff cam. infima-.ammi11Min,-or Batasuna, GERMANY.

Pnocn'ss or'f'rnn'ATINe a- 1 fsmtramite,k

To all whom t may concern: y

Be itknown that I, Fmnmuoit` CARDVVIL-` HELM T1MM,-a subject of vthe IEmperor' of Germany, residingatI-Iamburg, have invented new and 'useful Improvements in Processes v'of TreatingMetalliferous Ma-` and likePurposesf whichv the following ,1s

as eciication. l

y he invention relates y n of carrying.k out the so-called y blowing recess 1n itself familiar in metallurgy, as

` n potfroastingvfor the purpose of roasting,

reducing and sintering the like. o c

At thepresent timetie blowing is, as a together# ores` and rule, so carried'out'that thefifire gradually f advances through the u nited side' ofthe sametothe opposite side,

the charge being placedonxed ortraveling sgra'es-and being mixed with the total quantity of fuel necessary or naturally present,;

art of Vthe vand the air bein heated by thel yby therecharge already b own, abandone action zone, and

blowing is efectedg'according to thisfwell 'known manner,which disadvantages show o charge in lill themselves, for example, in the overheating i in some placesand insuflif'zient,heatingm others, 1n an lncompletely carried out 'reaf' ;k

tion, iny an irre ular settlement of the substance (particu arlyin the case of an..ex` cess ofl fuel and of fuel of a voluminous nature) and in similar'v ways; y

ll`he resent process, however, object t ecarrylng outof the blowing under suchl conditionsV that ythe transference of heat is well eii'ected everywhereV for asui` cient time at approximatelv the best rel,`

action temperature, and wthoutharmful overheatingy in single; places, andl ythat the n the` blown portion always liesvk with practically an equal density.`

The process conslstsin blowing a hot i charge. repeatedlv mixed with heatin "mathe4 quantitv ofhceting material employed 'is Specification of Letters Patent.

Germany n c after a certain -periodofblowin Reducing, Sintering, u

to al special methbd n `.charge from the ifgf hot;y But with; some ,rnatef rials considerablev disadvantages arise when lie transition stages.

ing to the of the metals'iron, lead, zinc, copper,

treatment Itassium and n v avaporswof volatile metals) or to lower METALL'IFERQUS "MATERIALS, Fon noastrme, aanname,

ND LiKE/PURPOSES. l n

heatmgmaterial is' againintroquantity as yhas been burnt out of l A u b y Vor unin terruptedly during the blowing. ,urthergit is .advantageous to mixthe charge not only charge, and afterward blowing again.

.On blowing substances which already contain-heating material, for example ores containingsulfur or mixed with carbon fresh substance lis' introduced into already blown,l

hot-substance, exactlyA like pureheating ma-y p terial. Then after a certain period of', blowmg, or after a certaln number o fmixingr and blowingk periods, theV charge consists' of a mixture, 1n one constituentpart of' which,

(the y greater `quantlty),

y c y the' arp'reprete' treatment rhas been effected very completely,

of ythe, charge, or of a.y

t n l n y l Patented; July 4,*191'6, Tippmannmacaroni-30,1915sma1m; 79s,17e. f v

maintained as regular as possible,and if for tlns` purpose duced into the chargefln about the samey it, either `with the 'added heating material but alsoin ,This

yso

andin the other,"(theksmaller quantity) it has-not yet been. completed;v between these f s In connection'y with resent process ,the blown substance there yy obtai 'ed' may; al'temaidr also they blowing accord# be further blowninthe familiarvmannlg for n example with a gradually advancing reaction' zone Lin the common pots, subjectedy to some 'other suitable treatment.r

I n the above description the words heat? in the chargey to beb'lown,

wheny present .i

their combustiom In parf evolve heat by fticular ysulfur and carbon or materials! con- (and) carbon are ythereby l y Butiron oiiother metals. n finely distributed lin the charge may alsokbe` used inquite asimilar manner.

taining sulfur or toibc understood.y

The process isdestinedffor-the oxidizing,

" lchloridizing, sulfatizing or .magnetic `roastforfexample I ing of ores or ptherfmaterials,

p silver, gold, arsenic, and `s oforth; for thek reduction of` oxids, hydroxide, carbonates, siii#ku cates',sulfids or sulfates for example ofy thev metals zinc, lead, copper, iron,} sodium, po-

so forth, to metals (metallic oxidation stages; for the `volatilization ofy metals or it 'maybe g ing material slgnify such mateials as,y

from oxids, sulfids or sulfates, with re-oxi- (lation (for example for zinc, lead, bismuth, arsenic, antimony, sodium, potassium and so forth) for sinterin and agglome 'ating zine ore, flue dust, pyrites residue, and the like; for reducing sulfatos to sullids, for example barytes to barium sulfid; and for other methods of treatment possible by blowing.

The air used tor blowing may be sometimes previously heated with advantage. In addition suitaole gases or vapors may be added to it, and its oxygen content may be increased or decreased. The air used for blowing or the gas may be introduced into the charge as well from above as from below or laterally.

In the present specification the expression blowing is used, for the sake of brevity, for a treatment by heat of fragmentary, especially minutely fragmentary or ioury substances, the heating material in question being distributed in the charge and being air or some other gas con* burnt out of it by ducted through by means of pressure or suc tion. Further, the limitation is also made that the charge is not brought by the blowing to the point of complete melting, but at the most of softening or of sintering.

The processis,in the case of roasting zinc blonde for example, carried out in the foilowing manner: Some blonde is introduced 'through an opening in the upper side into a closed converter provided with an air inlct through one trunnion and with a gas outlet through the other. By rotating the converter this is mixed with the rest of the contents, consisting of almost completely roast' ed blonde; the converter is stopped in a suitable position, and thcn blown for a comparatively short time. Thereupon the blast is cut oli', some roasted substance taken out, an appropriate quantity of blonde again filled in, this is again mixed by rotation with the rest of the contents, is again blown and so on. By suitably regulating the time of blowing in one period and the quantity of admixed raw blonde the heat may be maintained below a temperature causing a sintering of the materials, thus producing a product well adapted for subsequent reducing purposes. By the removal of the roasted substance at the sideat which the blast.

eqters, somewhere near the hearth in blowing in an upward direction, the smallest sulfur content may be obtained, and even this may be practically completely removed, in so far as it is not combined with alkalin earths, by blowing the removed hot substance with very little air in the usual manner.

If by way of example l part of raw blende with per cent. sulfur is added to some 9 parts of roasted blonde` then4 the sul-` fur content of the mixture rises by 3 per f/.inc onother volatile metals viously roasted, accordingr to cent., but with moderate preheating of the raw blends the temperature only sinks from about 1000D to about 930O centigrade. The air is also heated to just as high a tempel ture by the comparatively large quantity of the charge, very quickly after its entry into the same, and thus eilecting a'quick roasting. On the other hand -the small proportion o fuel (sulfur) to the charge has the effect that no harmful heating takes place near the support (grate). In this example about 8 per cent. by weight of the sulfur is removed from the charge in each blowing period, whereby the mean temperature again rises from 9250A3 to 10000 C. Instead of the proportion l to 9 of raw to already blown blonde, this may also be made for example l'to 3 or l to 20 or otherwise.

Another application of the process lies in the sulfatizing roasting of copper ores or ol complex lead-zine sullids, in order to subsequently leach out themetal contents. it being possible by making the content of heatiifg material small and by an appropriatc length of the blowing period, to keep thc temperature so low that there can be no destruction of the sulfate once formed. The same feature occurs in connection with a suliiciently lopg reaction period lwhich 4is favorable to the chloridizing roasting of copper ores, pyrites residu'es or the like, for the purpose ot'"snhsequ'ently leaching out the chloriu metal compound, or of` the chloridizing roastingr of oresior the ylike containing precious metals, especially gold or silver or other metals, as copptr,` loi-fthe purpose of volatilizing such mclals or hallal compounds (chlorin metal compounds), and to the nm'gnclizing roasting of iron orcs" for the purpose of magnetic separation. A\ccording to requirements in the various cases, one heating,r material (for example. sulfur) is supplcmcnted by another (for example,V fuels containing carbon). Further, as an advantageous application of the process, attention may specially be called to the recovery of such as lead, bismuth. antimony, arsenic or the like, either in the l'orm of vapors for the purpose of subsequent comicos-ation or of separation' as dust. or in the form of an oxygen compound for `the purpose of subsequent separation from the gases by filters or the like, from a mixture of solid carboircontaining materials (coal or coke) and ores that may be pre circumstances,

or other raw materials. Further, the process ris adapted to the roasting of line pylites, the

high sulfur content of which causes trouble in many ways with the usual 4method of blowing. In this case th main ioint is the recovery of sulfurous acit or sulfuric acid; similarly these. and by chloridizing roasting also hydrochloric acid, may be recovered in roasting other materials. i

` moving forward in L falls down throughy l n the illustration is shown by way of exam llein Fig. 1,8, longitudinal section and pin ig. 2 a cross section on theline X-X of Fig.

carrying out the process. l'lined with suitable 'fire-proof materials, is

1 of a .furnace specially suited for rlhe druinlA,

mounted on supporting rollers R andrunning-rings B, and for various` reasons is disposed preferably with a slight inclination. It may be rotated by driving devices not illustrated. T he air is introduced through the stationary pipe C, then passes over into the annular chambcrD connected with the drinn, and from there is conducted through pipes E into channels F which are covered over withv perforated plates C. H and I are closable 'doors the former serves for the admission of the substance to be treated, and the latter for the removal of finished substance. The heating lmaterial is filled into' the hopper K and taken out .of the same by a suitable feeding apparams, for example by a conveyer tube L,

provided with openings P, witha helix lying therein and driven by a pulley M. The' pi'pe L is connected with the drumr and rotates therewith'. The .heating material openings N along-the space c on tothe charge lying in-the drum, it being sometimes advantageous to bring about an unequal distribution/by means of a `variation in size of the openings N. 4Further,-tappets, not illustrated, are provided which actuate the cocks Sdn the pipes E in such a manner that only` those cpcks are opened which .put the channels Fl into connection with the `air conduit when at any time such channels are covered with a deep layer of matevto Agiven cases to rials while the rest ofthe cocks arecl'osed.

The gaseous products of Combustion escape intoftlie space O, to be led away, and iu be furtherytreated. Along the space al nov heating material falls down;

but here also air 1s driven through the charge', and this burns the heating material -still present orV ment ofthe substance being thus completed.

a part thereof, the treat- Thegcontents of the furnace gradually advance `from the supply side to .the emptying 1 side, and the 'treatment is in proportion to 'the forward movement.

If the furnace described -is used, for example, for volatilizing zinc from suitable materials, then these are admitted through the door H,and'through the hopper K on the other hand 'is admitted fine coal, coke, or thelike. But a mixture of both, such as for eiiamplel .the residual torts, may be admittedv exclusively through the hopper K, or Has-well as K may be used for the admission.j n roasting pyrites, blende. galena or similar materials, which already contain the heating .material ora urtion thereof in advance, theirV admission alone.

-quantity of the air,

ashes of zinc re- `-amount to the ispreferably effected through K and L The conditions of` pressure and`A as well as the number l ff rotations, are j preferably regulated in such a way that the appropriate cocks S are closed before the reaction has advanced quite through the charge up to the'upper surface. By thesemeans the highest content of sulfurous acid/ for example, may -be attainedf Insuch a furnace. the blowing is effected. with approximately continuous action: on rotation in the direction of the arrow, the channel F is connected to Ythe air conduit immediately after the closing of ther channel F1, and so on. In addition, that portion of the charge which #is under the blowing action at a given moment remains at `rest, for the movement (the 'slip-` effectedy at the upper surfacewhere no reaction `takes place. On their connection to the air conduit the pcrforatedplates (i are always covered with a charge lmixed inA itself with heatingl materials. s

1f no importance is attached to ycarrying lping down to the angle of' repose) is only on the working as continuously as possible,

the furnace illustrated may be fitted on one 'portion 'only of its inner surface with oneV suplgilemented as in the case of the process and the apparatus here described. Further, it has been proppsed to stir blonde during the blowing. But in the present process the portion of the charge subjected to blow',-

ing is kept at rest. In that case a further inarliof distinction also lies inthe gradual admission of heatingimaterial (sulfur) as against one single admission' in the known process. A

Claimsz l. The process of treating material consistingrin'introducing a charge of-such material intol a furnace, heating said charge and repeatedly adding solid heating materials to the hot furnace charge so that during the internall combustion only a portion of the total quantity of heating material necessary for treatment of the charge is present in the same. l

2. The process (iftreating material coii- 'i j sisting in introducing a charge of'sucli mateilo rial into a furnace, heating said charge and repeatedly adding a quantity of solid heating materials to the hot furnace charge, said quantity being approximately equal in quantity of material suii- 

